#pragma once

#include "util/BitField.h"

union spu_opcode_t
{
	u32 opcode;

	bf_t<u32, 0, 7> rt;     // 25..31, for 3-op instructions
	bf_t<u32, 0, 7> rc;     // 25..31
	bf_t<u32, 7, 7> ra;     // 18..24
	bf_t<u32, 14, 7> rb;    // 11..17
	bf_t<u32, 21, 7> rt4;   // 4..10, for 4-op instructions
	bf_t<u32, 18, 1> e;     // 13, "enable interrupts" bit
	bf_t<u32, 19, 1> d;     // 12, "disable interrupts" bit
	bf_t<u32, 18, 2> de;    // 12..13 combined 'e' and 'd' bits
	bf_t<u32, 20, 1> c;     // 11, "C" bit for SYNC instruction
	bf_t<s32, 23, 2> r0h;   // 7..8, signed
	bf_t<s32, 14, 2> roh;   // 16..17, signed
	bf_t<u32, 14, 7> i7;    // 11..17
	bf_t<s32, 14, 7> si7;   // 11..17, signed
	bf_t<u32, 14, 8> i8;    // 10..17
	bf_t<s32, 14, 10> si10; // 8..17, signed
	bf_t<u32, 7, 16> i16;   // 9..24
	bf_t<s32, 7, 16> si16;  // 9..24, signed
	bf_t<u32, 7, 18> i18;   // 7..24
};

constexpr u32 spu_branch_target(u32 pc, u32 imm = 0)
{
	return (pc + (imm << 2)) & 0x3fffc;
}

constexpr u32 spu_ls_target(u32 pc, u32 imm = 0)
{
	return (pc + (imm << 2)) & 0x3fff0;
}

constexpr u32 spu_decode(u32 inst)
{
	return inst >> 21;
}

std::array<u32, 2> op_branch_targets(u32 pc, spu_opcode_t op);

// SPU decoder object. D provides functions. T is function pointer type returned.
template <typename D, typename T = decltype(&D::UNK)>
class spu_decoder
{
	// Fast lookup table
	std::array<T, 2048> m_table{};

	struct instruction_info
	{
		u32 magn; // Count = 2 ^ magn
		u32 value;
		T pointer;

		instruction_info(u32 m, u32 v, T p) noexcept
			: magn(m), value(v), pointer(p)
		{
		}

		instruction_info(u32 m, u32 v, const T* p) noexcept
			: magn(m), value(v), pointer(*p)
		{
		}
	};

	// Helper
	static const D& _first(const D& arg)
	{
		return arg;
	}

public:
	template <typename... Args>
	spu_decoder(const Args&... args) noexcept
	{
		// If an object is passed to the constructor, assign values from that object
#define GET(name) [&] {                \
	if constexpr (sizeof...(Args) > 0) \
		return _first(args...).name;   \
	else                               \
		return &D::name;               \
}()

		static_assert(sizeof...(Args) <= 1);

		const std::initializer_list<instruction_info> instructions{
			{0, 0x0, GET(STOP)},
			{0, 0x1, GET(LNOP)},
			{0, 0x2, GET(SYNC)},
			{0, 0x3, GET(DSYNC)},
			{0, 0xc, GET(MFSPR)},
			{0, 0xd, GET(RDCH)},
			{0, 0xf, GET(RCHCNT)},
			{0, 0x40, GET(SF)},
			{0, 0x41, GET(OR)},
			{0, 0x42, GET(BG)},
			{0, 0x48, GET(SFH)},
			{0, 0x49, GET(NOR)},
			{0, 0x53, GET(ABSDB)},
			{0, 0x58, GET(ROT)},
			{0, 0x59, GET(ROTM)},
			{0, 0x5a, GET(ROTMA)},
			{0, 0x5b, GET(SHL)},
			{0, 0x5c, GET(ROTH)},
			{0, 0x5d, GET(ROTHM)},
			{0, 0x5e, GET(ROTMAH)},
			{0, 0x5f, GET(SHLH)},
			{0, 0x78, GET(ROTI)},
			{0, 0x79, GET(ROTMI)},
			{0, 0x7a, GET(ROTMAI)},
			{0, 0x7b, GET(SHLI)},
			{0, 0x7c, GET(ROTHI)},
			{0, 0x7d, GET(ROTHMI)},
			{0, 0x7e, GET(ROTMAHI)},
			{0, 0x7f, GET(SHLHI)},
			{0, 0xc0, GET(A)},
			{0, 0xc1, GET(AND)},
			{0, 0xc2, GET(CG)},
			{0, 0xc8, GET(AH)},
			{0, 0xc9, GET(NAND)},
			{0, 0xd3, GET(AVGB)},
			{0, 0x10c, GET(MTSPR)},
			{0, 0x10d, GET(WRCH)},
			{0, 0x128, GET(BIZ)},
			{0, 0x129, GET(BINZ)},
			{0, 0x12a, GET(BIHZ)},
			{0, 0x12b, GET(BIHNZ)},
			{0, 0x140, GET(STOPD)},
			{0, 0x144, GET(STQX)},
			{0, 0x1a8, GET(BI)},
			{0, 0x1a9, GET(BISL)},
			{0, 0x1aa, GET(IRET)},
			{0, 0x1ab, GET(BISLED)},
			{0, 0x1ac, GET(HBR)},
			{0, 0x1b0, GET(GB)},
			{0, 0x1b1, GET(GBH)},
			{0, 0x1b2, GET(GBB)},
			{0, 0x1b4, GET(FSM)},
			{0, 0x1b5, GET(FSMH)},
			{0, 0x1b6, GET(FSMB)},
			{0, 0x1b8, GET(FREST)},
			{0, 0x1b9, GET(FRSQEST)},
			{0, 0x1c4, GET(LQX)},
			{0, 0x1cc, GET(ROTQBYBI)},
			{0, 0x1cd, GET(ROTQMBYBI)},
			{0, 0x1cf, GET(SHLQBYBI)},
			{0, 0x1d4, GET(CBX)},
			{0, 0x1d5, GET(CHX)},
			{0, 0x1d6, GET(CWX)},
			{0, 0x1d7, GET(CDX)},
			{0, 0x1d8, GET(ROTQBI)},
			{0, 0x1d9, GET(ROTQMBI)},
			{0, 0x1db, GET(SHLQBI)},
			{0, 0x1dc, GET(ROTQBY)},
			{0, 0x1dd, GET(ROTQMBY)},
			{0, 0x1df, GET(SHLQBY)},
			{0, 0x1f0, GET(ORX)},
			{0, 0x1f4, GET(CBD)},
			{0, 0x1f5, GET(CHD)},
			{0, 0x1f6, GET(CWD)},
			{0, 0x1f7, GET(CDD)},
			{0, 0x1f8, GET(ROTQBII)},
			{0, 0x1f9, GET(ROTQMBII)},
			{0, 0x1fb, GET(SHLQBII)},
			{0, 0x1fc, GET(ROTQBYI)},
			{0, 0x1fd, GET(ROTQMBYI)},
			{0, 0x1ff, GET(SHLQBYI)},
			{0, 0x201, GET(NOP)},
			{0, 0x240, GET(CGT)},
			{0, 0x241, GET(XOR)},
			{0, 0x248, GET(CGTH)},
			{0, 0x249, GET(EQV)},
			{0, 0x250, GET(CGTB)},
			{0, 0x253, GET(SUMB)},
			{0, 0x258, GET(HGT)},
			{0, 0x2a5, GET(CLZ)},
			{0, 0x2a6, GET(XSWD)},
			{0, 0x2ae, GET(XSHW)},
			{0, 0x2b4, GET(CNTB)},
			{0, 0x2b6, GET(XSBH)},
			{0, 0x2c0, GET(CLGT)},
			{0, 0x2c1, GET(ANDC)},
			{0, 0x2c2, GET(FCGT)},
			{0, 0x2c3, GET(DFCGT)},
			{0, 0x2c4, GET(FA)},
			{0, 0x2c5, GET(FS)},
			{0, 0x2c6, GET(FM)},
			{0, 0x2c8, GET(CLGTH)},
			{0, 0x2c9, GET(ORC)},
			{0, 0x2ca, GET(FCMGT)},
			{0, 0x2cb, GET(DFCMGT)},
			{0, 0x2cc, GET(DFA)},
			{0, 0x2cd, GET(DFS)},
			{0, 0x2ce, GET(DFM)},
			{0, 0x2d0, GET(CLGTB)},
			{0, 0x2d8, GET(HLGT)},
			{0, 0x35c, GET(DFMA)},
			{0, 0x35d, GET(DFMS)},
			{0, 0x35e, GET(DFNMS)},
			{0, 0x35f, GET(DFNMA)},
			{0, 0x3c0, GET(CEQ)},
			{0, 0x3ce, GET(MPYHHU)},
			{0, 0x340, GET(ADDX)},
			{0, 0x341, GET(SFX)},
			{0, 0x342, GET(CGX)},
			{0, 0x343, GET(BGX)},
			{0, 0x346, GET(MPYHHA)},
			{0, 0x34e, GET(MPYHHAU)},
			{0, 0x398, GET(FSCRRD)},
			{0, 0x3b8, GET(FESD)},
			{0, 0x3b9, GET(FRDS)},
			{0, 0x3ba, GET(FSCRWR)},
			{0, 0x3bf, GET(DFTSV)},
			{0, 0x3c2, GET(FCEQ)},
			{0, 0x3c3, GET(DFCEQ)},
			{0, 0x3c4, GET(MPY)},
			{0, 0x3c5, GET(MPYH)},
			{0, 0x3c6, GET(MPYHH)},
			{0, 0x3c7, GET(MPYS)},
			{0, 0x3c8, GET(CEQH)},
			{0, 0x3ca, GET(FCMEQ)},
			{0, 0x3cb, GET(DFCMEQ)},
			{0, 0x3cc, GET(MPYU)},
			{0, 0x3d0, GET(CEQB)},
			{0, 0x3d4, GET(FI)},
			{0, 0x3d8, GET(HEQ)},
			{1, 0x1d8, GET(CFLTS)},
			{1, 0x1d9, GET(CFLTU)},
			{1, 0x1da, GET(CSFLT)},
			{1, 0x1db, GET(CUFLT)},
			{2, 0x40, GET(BRZ)},
			{2, 0x41, GET(STQA)},
			{2, 0x42, GET(BRNZ)},
			{2, 0x44, GET(BRHZ)},
			{2, 0x46, GET(BRHNZ)},
			{2, 0x47, GET(STQR)},
			{2, 0x60, GET(BRA)},
			{2, 0x61, GET(LQA)},
			{2, 0x62, GET(BRASL)},
			{2, 0x64, GET(BR)},
			{2, 0x65, GET(FSMBI)},
			{2, 0x66, GET(BRSL)},
			{2, 0x67, GET(LQR)},
			{2, 0x81, GET(IL)},
			{2, 0x82, GET(ILHU)},
			{2, 0x83, GET(ILH)},
			{2, 0xc1, GET(IOHL)},
			{3, 0x4, GET(ORI)},
			{3, 0x5, GET(ORHI)},
			{3, 0x6, GET(ORBI)},
			{3, 0xc, GET(SFI)},
			{3, 0xd, GET(SFHI)},
			{3, 0x14, GET(ANDI)},
			{3, 0x15, GET(ANDHI)},
			{3, 0x16, GET(ANDBI)},
			{3, 0x1c, GET(AI)},
			{3, 0x1d, GET(AHI)},
			{3, 0x24, GET(STQD)},
			{3, 0x34, GET(LQD)},
			{3, 0x44, GET(XORI)},
			{3, 0x45, GET(XORHI)},
			{3, 0x46, GET(XORBI)},
			{3, 0x4c, GET(CGTI)},
			{3, 0x4d, GET(CGTHI)},
			{3, 0x4e, GET(CGTBI)},
			{3, 0x4f, GET(HGTI)},
			{3, 0x5c, GET(CLGTI)},
			{3, 0x5d, GET(CLGTHI)},
			{3, 0x5e, GET(CLGTBI)},
			{3, 0x5f, GET(HLGTI)},
			{3, 0x74, GET(MPYI)},
			{3, 0x75, GET(MPYUI)},
			{3, 0x7c, GET(CEQI)},
			{3, 0x7d, GET(CEQHI)},
			{3, 0x7e, GET(CEQBI)},
			{3, 0x7f, GET(HEQI)},
			{4, 0x8, GET(HBRA)},
			{4, 0x9, GET(HBRR)},
			{4, 0x21, GET(ILA)},
			{7, 0x8, GET(SELB)},
			{7, 0xb, GET(SHUFB)},
			{7, 0xc, GET(MPYA)},
			{7, 0xd, GET(FNMS)},
			{7, 0xe, GET(FMA)},
			{7, 0xf, GET(FMS)},
		};

		for (auto& x : m_table)
		{
			x = GET(UNK);
		}

		for (auto& entry : instructions)
		{
			for (u32 i = 0; i < 1u << entry.magn; i++)
			{
				m_table[entry.value << entry.magn | i] = entry.pointer;
			}
		}
	}

	const std::array<T, 2048>& get_table() const noexcept
	{
		return m_table;
	}

	T decode(u32 inst) const noexcept
	{
		return m_table[spu_decode(inst)];
	}
};

#undef GET